Distortion and image collapse with SACD thru headphones?
Nov 28, 2002 at 2:08 AM Thread Starter Post #1 of 26

Calanctus

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SACD player owners, have you ever noticed that SACDs through your headphones suffer from the aforementioned distortion and image collapse? A post on Audiogon (http://www.audioasylum.com/forums/hi...ges/80361.html ) from a recording engineer (I think he's with Telarc) suggests that this can happen, and may be due to headamps' inability to deal with frequencies beyond 20KHz.

I haven't particularly noticed it myself. However, I'm using a Headroom Max these days, which the guy suggests may not be subject to this problem. He says that SACD players have a 'gentle filter' (whazzat?) so may not have this problem quite so badly as the DSD outputs that he listens to in the studio.
 
Nov 28, 2002 at 2:24 AM Post #2 of 26
What do you expect when you are dealing with a 6 bit system (SACD) that is pure junk at and above 8000 Hz?

I could hear the awfulness of this format straight away when I auditioned an SACD player from my dealer. After a week I was convinced that SACD was just plain rotten. I've been trying to find out just why that is and have finally gotten to the dirty truth:

http://www.iar-80.com/page38.html

Please read all of this long and detailed article.
 
Nov 28, 2002 at 2:46 AM Post #3 of 26
Calanctus, don't worry -- the bandwidth of the opamp used in the Headroom Max (OPA627) is more than sufficient for it to remain stable at frequencies above 20kHz.

As for the limitations of SACD, I agree with you Pepzhez, but I'm definitely in the minority around here. But it would be bad to get this thread off track...
 
Nov 28, 2002 at 3:17 AM Post #4 of 26
I wouldn't take anything in that IAR article too seriously. It's got serious misconceptions and wrong conclusions. This is not to say DSD (SACD's encoding method) is perfect, but the IAR article is really wrong.

DSD does have high suprasonic noise content (signal above 20 khz), and has been known to drive speaker amplifiers and preamps to instability.

--Andre
 
Nov 28, 2002 at 3:28 AM Post #5 of 26
Sure haven't heard it. On the contrary, the SACD version has a far superior soundstage to Redbook.

BTW: this "problem" would affect any component in the signal path of the SACDP-- pre-amps, amps, and speakers, too-- not just headamps.

Quote:

What do you expect when you are dealing with a 6 bit system (SACD) that is pure junk at and above 8000 Hz?


So, let's see, according to Perphez, there is little or no information above 8KHz due to limitations of SACD, making it inferior to Redbook. The poster on audioasylum says the opposite, that all the information SACD is able to pass above 20Khz (that Redbook can't) is what causes the problem.

Well... which is it?
tongue.gif


I say, none of this means a thing until you've heard it for yourself. That's all the "information" you really need.
smily_headphones1.gif


Mark
 
Nov 28, 2002 at 3:38 AM Post #6 of 26
In my experience, using the Sony XA777ES and Max (with HD600/Cardas), the soundstaging is BETTER with SACD than with CD.

Pure DSD recordings that I have (Telarcs, for instances) sound the most natural/life-like I have yet heard--NATURAL high frequencies (not too harsh, not too smooth, just NATURAL).

I believe the improved soundstaging I hear must be due to DSDs ability to capture more of the high frequencies.

The fellow on Audioasylum I believe was comparing his speaker/amp setup to his headphone setup, which included the Grado RS-1 and Grado amp, right? The Grados are known to be a bit on the bright side (at least that's how I hear them, compared to the HD600s).
 
Nov 28, 2002 at 4:24 AM Post #7 of 26
Of the titles I've heard that have both SACD and Redbook versions, SACD blows away Redbook in every way.

That includes hybrid discs where both the SACD and the Redbook versions have been remastered (so it's not just the remastering that makes SACD better).

It's clear to me that the guy who wrote that "article" has a bone to pick and his own agenda. Every unbiased comparison I've read of DVD-A and SACD has picked SACD. One of the biggest complaints about DVD-A is that on high-end systems, DVD-A's watermark is clearly audible.
 
Nov 28, 2002 at 2:01 PM Post #8 of 26
I agree with MacDEF.

I would also add that, although I haven't yet heard DVD-A,
theoretically it could sound as good as SACD. The problem is that, because of the DVD specs, multi-channel DVD-As don't currently have the full bandwidth (24/192), due to space limitations on the disk. And, of course, the watermark issue effects the sound also (although I haven't listened to DVD-A, many who have say the watermarking is pretty easy to hear).
 
Nov 28, 2002 at 2:28 PM Post #9 of 26
NO! The image is good through headphones and not signifigantly different from cd. What difference there might be would be in sacds favor. SACD images much better through my speakers. Image height is particulaly improved. The image just doesnt gain width and depth, it actually lifts off the floor. When I SWITCH BETWEEN CD AND SACD this is noticeable everytime. I love sacd, as you may have noticed.
wink.gif
 
Nov 28, 2002 at 9:53 PM Post #11 of 26
First I have to admit that I don't know much about digital techniques. But after reading (part of) the – awfully detailed and repetitive – article (http://www.iar-80.com/page38.html) that Pepzhez has brought into play, I must agree that theoretically the SACD format, which I always have sympathized with, has some problems with high-frequency amplitude resolution.

It's not accurate, as the author did, to speak of «64-fold oversampling». In fact it's a true sampling with 2.8224 MHz, not sort of interpolation. And that's exactly the 64-fold of the redbook sampling frequency of 44.1 kHz, therefore 6 bit at 44.1 kHz. As a consequence, the 1-bit system has 128 steps at its disposal for a 22.1 kHz sine wave (corresponding to 7 bit), 176 steps for 16 kHz (corresponding to 7.47 bit) and 256 for 11 kHz (8 bit). I really doubt this is enough and fear it could have serious consequences for the sound.

Myself I had a brief audition shortly; the SACD layer sounded clearly better in terms of overtone reproduction (of a cello) without having any shortcomings compared to the CD layer. This must not mean that the above mentioned has no relevance. For it's clear that the extended bandwidth brings a better articulation and transient response. (This despite the author's explicitely opposite standpoint). But in fact there could be some flaws which might only appear in comparison to a more accurate and better resolving system than the CD, i.e. DVD-Audio. I really can't deny this possibility.

Although I find it impossible to struggle through the whole article, I got the impression that the reviewer (J. Peter Moncrieff or who?) has done a very serious listening and knows what he's talking about. Just one objection: I have'nt found any declaration of the decoding (DAC) equipment, just «...played back through the professional master digital decoders of the two competing systems» – as if these must be taken both as the nonplusultra of their category and therefore free from any influence on the sound. But that's the only obvious point of criticism I have found in this review. So I must confess that I'm a bit shocked... I guess I have to take this article seriously. But what do I know in the end...

Is this the time to swap to DVD-A?

smily_headphones1.gif
JaZZ
 
Nov 28, 2002 at 10:47 PM Post #12 of 26
Thanks to the on-topic posters.

I did not want to start any discussion of the general merits of SACD, or of SACD versus DVD-A, since that has been done to death, but I suppose any mention of hi-rez media sets off those with an axe to grind.
 
Nov 28, 2002 at 11:23 PM Post #13 of 26
Calanctus...

...it seems to me that there's not much to say about the virtual phenomenon you are interested in: The SACD's HF noise is a fact, so it's possible that some electronics, amps included, suffer from interferences. But there's no reason why headphone amps should be specially susceptible to it. And finally any virtual interference is part of the SACD sound and possibly indistinguishable from it.

BTW, I was just concerned about what I've read, without any intention to heat up a «war». There's simply a lot of interesting new stuff to occupy with, and if that's happening in an SACD-related thread, it can't be that bad.
 
Nov 29, 2002 at 10:27 AM Post #15 of 26
Quote:

Originally posted by JaZZ
It's not accurate, as the author did, to speak of «64-fold oversampling». In fact it's a true sampling with 2.8224 MHz, not sort of interpolation. And that's exactly the 64-fold of the redbook sampling frequency of 44.1 kHz, therefore 6 bit at 44.1 kHz.


That's exactly the 64-fold of the redbook sampling frequency of 44.1 kHz, therefore it 64 bits at 44.1, not 6! Let's calculate again: SACD sampling frequency is 2.8224 MHz, i.e. 2.8224 megabits per second. If it's sampling rate was 44.1 kHz (as in redbook), each sample would contain 2822.4/44.1=64 BITS (not states!), which is 4 TIMES greater than redbook's 16 bits. In terms of bitrate, SACD even surpasses PCM 96/24. Though it's unfair to compare two completely different methods by their bitrates, it would be safe to assume that sonically SACD must be AT LEAST as good as PCM 96/24.
 

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